Party-line indicating-key.



. G. M. GAMPBELL. PARTY LINE INDIGATING KEY. l APPLIUATION FILED APR. 1'1, 190s.

' 911,377. aftena Eeb.2,'19o9.

UNrTnsTATEs PATENT onirica'.

GUY M. CAMPBELL, OF CHICAGO, ILLINOIS, ASSIGNOR TO KELLOGG SWITCHBOARD AND SUPPLY COMPANY, -OF CHICAGO, ILLINOIS,.A CORPORATION OF ILLINOIS.

PARTY-LINE INDICATING-KY.

To all whom it may concern: Y

Be it known that I, GUY M. CAMPBELL, ai citizen of the United States, residing in Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Party-Line Indicating-Keys, of which the following is a specification.

My inventionrelates to operators indicating keys or ringing keys used .intelephone switchboards for connecting ringing current with telephone lines-upon which a'plurality of substations are connected. ,y

It has been found desirable to provide some means by which the operator may be informed which one of the parties Vupon the tele hone line with whichthe key is temporar' y connected ,has been last called, and it is the object of my invention to provide a key which indicates the lastkey operated in a positive and distinct manner, and in a manner readily perceived either by sight or by touch. v

, It has been proposed inthe past to indicate the last key operated by causing the button itself to remain in a partially depressed position until another button has been actuated, and it has also been proposed to indicate the last button by means of an auxiliary signaling device such as a plunger operating in a position in proximity with the buttons.

With the former'arrangement a very longl stroke is required to the button in order that its three different positions shall be distinct, and in the latter arrangement the operating plungers tend to hide the indicating plungers from the ready view of the operator.

By my present invention I place an auxiliary plunger within the actuating. plunger, this auxiliary plunger carrying a target of a color contrasting withthe color of the button itself and normally standing on a level with the top surface of the actuating button. When a button is depressed this target is likewise depressed, but when the button is released the target is retained in a depressed position so that not only the appearance of the top of the button is changed but also the feeling of the button is so changed that the operator would realize from the touch whether or not the key was the one last depressed. Y c

It may be found desirable in some instances to cover the face of the button with transparent glass or celluloid in which case the advantage of the touchindication issacrificed v Specification of Letters Patent.

Application filed April 17, 1908. Serial No. 427,700.

`4 which form the key frame.

Patented Feb. 2, 1909.

l `though it is to be understood that my invention contemplates all modifications within the scope of mechanics7 skill.

My invention is illustrated in the accompanying drawing forming a part of this specificaticn, in 'which- Y Figure 1 is a plan view,l Fig. 2 is a front elevation; Fig. 3 is a section on the line 3 3 of Fig. 2 showing the indicating plunger in its normal position Fig. 4 is a section on the line 3 3 of Fig. 2 showing the indicating plunger in its indicatin position, and Fig. 5

is a fragmentary rear e evation.

The preferred embodiment of my invention comprises the top p late 1, pillars 2 and 3, andthe insulating spring supporting strip The actuating plungers 6 extend through alined openings in 'the spring supporting strip 4, the top plate 1 and the rubber escutcheon 7 and carry the actuating buttons 8 secured to their uppermost ends. These plungers are cylindrical in formand have the enlarged guiding portions 9 which prevent the plungers from turning and also form the abutments which limit the upward movement of the plungers. Coil springs 10 are disposedabout the plungers between the abutments 9 and the spring carrying strip 4 and tend to hold the actuating plungers in their uppermost positions. Each actuating plunger has a hole therein extending from the top down to the'point 12 and contains the auxiliary plunger 13 so mounted that it is free to reciprocate slightly, the amount of reciprocation being limited by the length of the slot 14 through which the pin 15, which is secured in the plunger 13, extends.

Within the tubular portion of the plunger 6 and below the plunger 13 is a coil spring 17 which tends to hold the auxiliary plunger in its uppermost position within the operating plunger. This spring, however, is much weaker than the spring 10 which raises the actuating plunger. These auxiliary plungers carry targets 11 of a color contrasting with the color of the buttons, their upper surfaces being normally flush With the upper surfaces of the actuating plungers. The

late 18 which carries `a plurality of catch hngers 19 is pivotally supported by the screws 20 between the columns 2 and 3. This plate also carries the finger 21 which extends above the face of the key in a position accessible to the operator. The ends of the lingers 19 are turned inwardly to form the catches Which are adapted to engage the ends ot the pins 15 when the plungers carry# ing these pins are depressed to their lovfest positions. rlhe spring shown in 5 gives the top oi the plate 1S a normal inward tension so that the catches are in position to engage the pins 15. Eael. plunger carr'es a spring actuating knob 2l adapted to b forced between the springs 25 to actuate these springs when the plunger is depressed.

When any actuating plunger is depressed, the pin 15 carried by the auxiliary plunger 1.3 passes the catch 22 o' the linger 19, slightly moving the plate 18 and the catch lingers carried thereby upon its pivots 2t) but when the actuating plunger is released tle pin 15 of the auxiliary plunger' is engag l by the catch 22 and the auxiliary plunger and its indicating target 11 are retained in their depressed position. The appearance et the key is new materially altered in that the target 11 of the last depressed plungerl is held at a slight distance below the upper surface of the button, and inasmuch as the key is seldem it ever in practice viewed from directly above, the difference in appearance between this button and the other buttons is very prominent. When any other button is depressed the catch plate 18 is again moved and the auxiliary plunger formerly depressed is released and is returned to its normal position by the ex ansion of spring 17.

A listening zey is usually associated u'ith ringing keys oi this class and is preferably mounted in the same structure with the ringing buttons. Such a key is illustrated at the lett end o'l the structure and comprises the operating cam 26 adapted When tilted about the pivot 27 te reciprocate the plunger 28 so that the knob 29 will be forced between the slanting ends ot' the springs 30 to co itrol the circuit through the contacts carried by said springs.

While l have shown and described my invention with respect to a particular structure, l do not Wish to be unduly limited thereto, many alterations beinOV possible Without in any Way departing from the spirit or scope o1" my invention.

l claim:

1. ln an operators indicating key, the combination with a plurality oi actuating buttons, of a plurality of indicating targets, one carried Within each ot the actuating buttons, the target associated with the last button actuated being held below the surface oi the button to indicate that its associated button Was the last actuated, substantially as described.

2. In an operaters indicating key, the combination With a suitable supporting frame, of a plurality oi suf'itch actuating buttons, a plurality ot' vertically reciprocating targets, one located Within each ol the said buttons, indicate substan and adaiiitcd by their positions to the last ol said buttons actuated, ally as dcscril ied.

3. lu an opci'atous indicating key, the combinatirui with a suitable supporting -trame, et' a plurality oll actuating plungers, a plurality el" auxiliary ,iliugcrs, one located -within each ol said actuating pluugers, and means to retain the auxiliary plunger associated with the last operated actuating plunger in a depressed position. to indicate tluit its associated actuatinjg plunger uan the last operated, subsu rtially :is dcscriluid.

1l. lu an operatorls imlicating key, the combinatimi with a plurality olf actuating buttons, cach having an opening tlicrcthrongn oi a plurality tl indimiting targets of con. ting colors, or-e in cach olI said openings, and means to move said targets 'trom their normal position to indicate thc last button actuated, substantially as described.

5. In an operators indicating key, the combination with a suitable trame, ol a plurality of switch actuating` plungcrs, a plurality of auxiliary plungers, one carried witbin each ot said actuating` plnngers, und means to retain one of said auxiliary plungers in. a depressed position alter its associated actuating plunger .lias been depressed and released, substantially as described..

6. ln an operators indicating key, the combination with a suitable frame, ol2 a plurality of switch actuating plungers, a plurality of auxiliary plungers, one carried witbin each ot said actuating plungors, and a catch plate pivoted on said trame adapted to retain said auxiliary plungers in a dcpressed position atter the'` associattul :ictuating plungers have been depressed and released, sulstantially as described.

7. ln an operator-s indicating key, the combination with a plurality of vertically reciprocating plunger-s termed ol two distinct portions, ot means to retain one portion of each or said plungers in a depressed position after the other portion has returned to normal position to indicato the last ol said plungers actuated and released, substun tially as described.

S. ln an operators indicating key, the combination with a plurality ot vertically reciprocating members, ol means to displace a portion only et each ol said members from. its normal position to indicate the last button actuated and released, substantially as described.

9. ln an operator-s indicating key, the combination with a plurali@T olf actuating means, ol means to retain a portion ol each ot' said actuating means in an almornial position when the rest et the same actuating means is depressed and returned to its normal position, said retained portion being released When any other actuating means is dcpressed to its `actuating position and` a spring for returning the`released ortion to its normal position, substantial y, as described.

10. In an operators indicating'key, the combination with a plurality of sets of switch springs, of a plurality of actuating means, one for each of said sets of switch s rings, buttons for said actuating means, eac button having portions of contrasting colors, one of said portions of the buttons being adapted to be withdrawn from the ready View of the operator to indicate the last button actuated, substantially as described.

11. In an operators indicating key, the combination of a plurality of switch actuating means, each normally exposing portions of contrasting colors, and means to remove `one of said portions from the ready View of the operator to indicate the last actuating means operated, substantially as described.

l2. In an operators indicating key, the combination with a plurality of actuating means, each exposing portions oi contrasting colors, of means to obscure one of said portions fromy the last actuating means operated and means to display said portion when any other of said actuating means is operated, substantially as described.

Signed by me at Chicago, county of Cook,

and State of Illinois, in the presence of two GUY M. CAMPBELL.

witnesses.

Witnesses: Y

CLIFFoRD C. BRADBURY, MARJORIE E. GRIER. 

